How to join plastic and metal without screw?

Hi guys,

I’m trying to join 2 plates of abs and metal without using a screw because the maximum thickness allowed should be the thickness of the abs + the metal = 6mm. So no screw head protruding and the joint should not be visible on the upper part, and no glue.
I have 3 ideas here:
join

  1. What I call headless screws, but there is not much thickness I’m afraid it will not hold long.
  2. I often see this kind of thing between 2 plastic pieces (one piece hangs on inside the other) but here I wonder if it will work with metal.
  3. I imagine a kind of screw that retracts when it enters and keeps this position inside.

Any ideas?
Thank you.

Glue them together instead?

What’s the application? How large are these pieces? Is there going to be a lot of force on them? Force in which direction?

Routing a T-slot into the plastic would let you put something like screw 3 into it. But I don’t think the plastic side is your worry, there’s enough on that side for a screw to grab.

If it’s mainly shear force trying to slide the pieces across eachother (left to right in your picture) then just a smooth stud welded to the steel would hold that, but would do nothing to keep the pieces from being pulled apart (up and down in your picture).

Another good option. Do you need the ability to disassemble these?

Good questions, the only force applied is on the lip of the plastic directed upwards and the metalic part is fixed and it should also avoid shearing even if no force is applied.
Pieces are about 350x20mm.
A T-slot :thinking: interesting… so in order to avoid to slide i could in addition to T-slot add a screw like n°1.

A common thing I’ve seen here when the joint is to be permanent is plastic posts melted in place, basically plastic rivets integrated into the body of the plastic.

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I was thinking about that but did not know how to call it, plastic rivets, thanks. But in my case the integration will not be easy integrate afterwards.

Heat staking is what I’d call that

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Plastic rivets are used a lot in cars. They’re essentially pop rivets made of plastic - they want to pass through both sheets. On one side a head stops them going through, on the other side the rivet expands (various mechanisms)

Thank you! I’d seen the results but didn’t know the name. Today I learned…

Yes I see the problem has been solved …
But if you will allow … I would also mention double sided tape.
It is such a useful solution for so many assemblies I keep many different sizes and brands on the shelf.